All I did was change the material and voila, problems galore.

All I did was change the material and voila, problems galore. Infact, just 2 problems.

  1. See those consistent gaps in z axis?
  2. The consistent gaps in the first few layers. The gap is regular whichever direction it prints. I thought it could be the spool resistance but even with slack it is regular.
    I am sure you have seen this happen before. Can you please help troubleshooting this issue?
    I am printing a brand new Pla from Solid scape in India.

if you change back to your old material - is the Problem really gone? Maybe something else changed without you noticing. Have you checked Filament diameter? Maybe you had bit overextrusion which covered these rings and now they are just more visible…
Maybe your z-axis… is the distance equal to the ptich of your z- rod leadscrew. else check the slicer or g-code maybe every n- layer direction changes (cw/ccw).
https://www.simplify3d.com/support/print-quality-troubleshooting/#lines-on-the-side-of-print

Filament is the single largest variable in changing print properties. I thermally calibrate each spool of filament I use to minimize these variations with excellent results.

@Ulrich_Baer I used up my old material. I use 5mm threaded rod for which Prusa recommends 0.3mm height.

@Jeff_Parish I will do thermal calibration again today. Thanks

@Kamesh_M_Sundaram These are the clips I use for my thermal calibrations.

and

Perhaps dirt in the extruder gear, it then sticks or slips once per revolution, losing steps. Also try higher extruder stepper current. I also had something similar from an overheating stepper driver, put a fan or good ventilation on the stepper drivers. Is the Z-axis smooth? it may also be jumping. Look for correlation once per rev to the height of the error.

do you have a ac unit`?

I am almost certain that is what is referred to as Z-banding, measure the gaps and see if they match the thread pitch of the Z-axis. If so then you need to check for anything loose on your Z.